R5RS does not specify 'ë'. It's just another character like 'A' or 'a'. In Racket, the language, ë and lambda are equivalent.<br><br><div class="gmail_quote">On Mon, May 14, 2012 at 11:09 AM, Michael Rice <span dir="ltr"><<a href="mailto:limitcase@gmail.com" target="_blank">limitcase@gmail.com</a>></span> wrote:<br> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div>The code below (kons) gets flagged in R5RS: </div><div><br></div><div>define: not allowed in an expression context in: (define dispatch (ë (m) (cond ((= m 0) x) ((= m 1) y) (else (error "Argument not 0 or 1 -- KONS" m)))))</div> <div><br></div><div>Works fine if I replace the lambda symbols with "lambda".</div><div><br></div><div>Cause?</div><div><br></div><div>Michael</div><div><br></div><div>============= </div><div><br></div><div>From page 91 in SICP (slightly modified):</div> <div><br></div><div>(define kons (ë (x y)</div><div> (define dispatch (ë (m)</div><div> (cond ((= m 0) x)</div><div> ((= m 1) y)</div><div> (else (error "Argument not 0 or 1 -- KONS" m)))))</div> <div> dispatch))</div><div><br></div><div>(define (kar z)</div><div> (z 0))</div><div><br></div><div>(define (kdr z)</div><div> (z 1))</div><div><br></div> <br>____________________<br> Racket Users list:<br> <a href="http://lists.racket-lang.org/users" target="_blank">http://lists.racket-lang.org/users</a><br> <br></blockquote></div><br>